1. Chop the tomatoes into evenly sized chunks or slices.
2. Slice the shallots or onions thinly and peel and slice the garlic cloves.
3. Lay the herbs on the base of an oiled baking tray. Place the tomatoes, shallots, onions and garlic on top and drizzle with the oil and balsamic vinegar and sprinkle with the sugar, salt, and pepper.
4. Roast in a 180°C oven for an hour or so until they’re soft and unctuous.
5. Remove from the oven and remove any woody pieces of herb. Then whizz in the food processor until the mixture is smooth.
6. Pass through a sieve to remove any seeds or bits of tomato skin or stalk.
7. Check the seasoning and then pour the still-warm mixture into hot, sterilised jars. Tighten the lids well.
8. Stand the jars in a large saucepan and cover with warm water. Slowly bring it to the boil and simmer for fifteen minutes to sterilize everything properly.
9. Leave to cool before checking that all the lids are now depressed. If any aren’t, you’ll need to use that jar of passata within the next couple of days. Otherwise they will keep in a cool, dark place for months.
Serve as it is on pasta with some freshly grated Parmesan cheese or use it as the base for the most fantastic spaghetti bolognese you’ve ever eaten.